This policy setting allows user-based policy processing roaming user profiles and user object logon scripts for interactive logons across forests.This policy setting affects all user accounts that interactively log on to a computer in a different forest when a trust across forests or a two-way forest trust exists.If you do not configure this policy setting:- No user-based policy settings are applied from the user's forest.- Users do not receive their roaming profiles; they receive a local profile on the computer from the local forest. A warning message appears to the user and an event log message (1529) is posted.- Loopback Group Policy processing is applied using the Group Policy Objects (GPOs) that are scoped to the computer.- An event log message (1109) is posted stating that loopback was invoked in Replace mode.If you enable this policy setting the behavior is exactly the same as in Windows 2000: user policy is applied and a roaming user profile is allowed from the trusted forest.If you disable this policy setting the behavior is the same as if it is not configured.